Cejas Cooling & Construction

Between Loss and Load

Between Loss and Load: The Audit That Cuts to the Bone

Some truths only come to light under pressure—others need a blower door, a thermal imager, and a keen eye for the leaks that drain comfort from our homes. Energy audits are less about saving pennies and more about tuning the soul of a structure. This is where good homes become great ones.

Four Organizations That Offer Energy Audit Certifications

  1. BPI (Building Performance Institute)
  2. RESNET (Residential Energy Services Network)
  3. DOE (U.S. Department of Energy) – through its Home Energy Score program
  4. ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers)

Three Broad Categories of a Residential Energy Audit

  1. Walk-Through Audit – Visual inspections, basic diagnostics.
  2. Standard Audit – Includes diagnostics like blower door and duct testing.
  3. Comprehensive Audit – Combines diagnostics, combustion testing, thermography, and detailed reporting.

Defining the Invisible: Thermal Boundaries, Bypass, and Intermediate Zones

  • Thermal Boundary: The shell that separates conditioned from unconditioned space.
  • Thermal Bypass: Gaps that allow unwanted heat transfer.
  • Intermediate Zones: Areas not fully inside or outside—like uninsulated attics or crawlspaces—that confuse airflow and heat exchange.

The Five Diagnostic Tests

  1. Blower Door Test – Measures air leakage.
  2. Duct Leakage Test – Finds leaks in duct systems.
  3. Combustion Analysis – Checks for flue gas safety and efficiency.
  4. Infrared Thermography – Visualizes insulation gaps and thermal bridges.
  5. Zonal Pressure Diagnostics – Assesses pressure imbalances in rooms.

Health and Safety in the Context of Energy Audits

Seal too tight and the air turns stale. Miss a combustion leak and the air turns deadly. A good audit checks:

  • CO levels
  • Draft and spillage from combustion appliances
  • Adequate ventilation for indoor air quality

Infrared Scanning: Seeing the Ghosts in the Walls

A thermal imaging camera captures temperature differentials on surfaces, exposing missing insulation, air leaks, and hidden moisture. It’s like reading the house’s autobiography in heat.

Why Sealing Air Leaks Matters

Every unsealed gap is a siphon for conditioned air. Seal them, and the HVAC system doesn’t fight gravity and entropy all day. Less energy, more comfort.

Duct Leakage Tests: How and Why

  • Total Leakage Test: Measures air loss from ducts in all directions.
  • Leakage to Outdoors Test: Measures only air leaking outside the thermal envelope.

The Blower Door Test

A fan pressurizes or depressurizes the house, and sensors measure how quickly pressure equalizes. Reveals leaks like wind on a beach exposes footprints.

Combustion: Perfect, Complete, and Incomplete

  • Perfect: Rare, ideal ratio of fuel and oxygen. All fuel becomes CO2 and water.
  • Complete: Achievable. Efficient burn, minimal waste.
  • Incomplete: Produces CO, soot, unburned hydrocarbons. Dangerous and wasteful.

Combustion Air and Efficiency

Good combustion needs air—too much and it’s diluted, too little and it’s suffocated. The sweet spot is where heat meets safety.

Draft and Venting

Draft carries combustion gases safely out. Poor draft = backdraft. Good venting uses stack effect, proper sizing, and material to keep poison outside where it belongs.

Flame Safeguard Controls

  1. Thermocouples – Proves flame presence.
  2. Flame Rods – Conduct electricity through flame.
  3. Photoresistors – Sense visible flame light. Each is a sentinel, shutting things down when fire misbehaves.

Furnace Design Tiers

  • Standard: Basic, low-efficiency.
  • Mid-Efficiency: Vent with metal flue, around 80% AFUE.
  • High-Efficiency: Condensing, plastic venting, 90%+ AFUE. Extracts every usable Btu.

Routine HVACR Maintenance

  • Change filters
  • Clean coils
  • Inspect combustion chamber
  • Test safeties
  • Calibrate thermostats

Why Numbers Matter in an Audit

Audits are not guesswork. CFM, Btus, % leakage—they all tell the story of how energy moves, escapes, or stagnates.

Base Load vs Seasonal Usage

  • Base Load: Energy used year-round (lighting, water heating).
  • Seasonal Load: Varies with HVAC usage. Spikes in summer and winter.

The Energy Index

A benchmark score that quantifies a home’s efficiency. Lower number = higher performance. It’s the SAT score of your building envelope.

An energy audit isn’t just about bills—it’s about control. About knowing where your house breathes, sweats, and shivers. When done right, it’s not just a report. It’s a diagnosis. A blueprint for balance. Next up: the bones and nerves of combustion itself.